Abstracts Category : Other

Propagation model for cellular mobile networks used in UAVcommunications environmentss

by Andr de Silvrio

Recognizing the growth of the drone market in recent years, it is crucial to evaluate thecapacity of the mobile communications technologies as well as their infrastructure toverify if these are capable to support various applications and services that may associatewith these type of vehicles, achieving lower costs to the users. The type of applicationchosen for this thesis is a video streaming that is able to assume different qualitiesdepending on the RF conditions, in order to overcome the limitation of radiocommunications, in which the user is only able to communicate with the drone when inhis line of sight.It was necessary to take into account a propagation model that considered the uniquecharacteristics of an UAV, since the most commonly used models only consider a typicalmobile user moving below the level of the BSs and their respective antennas using ashort/medium frequency interval that is not able to consider the third and fourthgeneration technologies at once. In order to choose the ideal model, a theoretical studywas carried out, which allowed to conclude that Lisbon University Institute Model is themost accurate since it is able to fulfill the requirements associated to a flying drone,considering a larger frequency spectrum, allowing the use of third and fourth generationtechnologies that are fundamental to support multimedia services, such as videostreaming.To verify the viability of mobile communications, measurements were made in three realscenarios in rural areas using a spectrum analyzer carried by a flying drone, in order tomonitor, read and write the data related to the signals behavior into a file, during theflight route.Based on this approach, it was possible to analyze the viability of mobile communicationsfor a video streaming service using a drone, in a rural environment and considering UMTSand LTE technologies. In addition, evaluate the signals performance when the drone isabove the antennas where the hole phenomenon occurs, theoretically. Tendo em conta o crescimento que o mercado de drones tem tido nos ltimos anos, importante considerar as tecnologias de comunicaes mveis assim como as respectivasinfraestruturas e verificar se estas so capazes de suportar diversas aplicaes que podemestar associadas a estes veculos, permitindo isto um custo inferior para os utilizadoresdos mesmos. O tipo de aplicao escolhida para esta tese foi uma streaming de vdeo,com o objetivo de ultrapassar a limitao das comunicaes rdio, em que o utilizadorapenas consegue comunicar com o drone caso este se encontre no seu campo de viso.Foi necessrio ter em conta um modelo de propagao que considerasse as caractersticasnicas de movimentao dum drone, uma vez que os modelos mais utilizados apenasconsideram um utilizador mvel comum que se desloque abaixo do nvel das estaesbase e respetivas antenas para um espectro de frequncias curto/mdio. Para a escolhadeste modelo, foi realizado um estudo terico que permitiu concluir que o LisbonUniversity InstituteAdvisors/Committee Members: Amaro, Pedro Joaquim, Almeida, Alexandre.